Hydrocarbons may be produced from wellbores drilled from the surface through a variety of producing and non-producing formations. The wellbore may be drilled substantially vertically or may be an offset well that is not vertical and has some amount of horizontal displacement from the surface entry point. In some cases, a multilateral well may be drilled comprising a plurality of wellbores drilled off of a main wellbore, each of which may be referred to as a lateral wellbore. Portions of lateral wellbores may be substantially horizontal to the surface. In some provinces, wellbores may be very deep, for example extending more than 10,000 feet from the surface.
A variety of servicing operations may be performed on a wellbore after it has been initially drilled. A lateral junction may be set in the wellbore at the intersection of two lateral wellbores and/or at the intersection of a lateral wellbore with the main wellbore. A casing string may be set and cemented in the wellbore. A liner may be hung in the casing string. The casing string may be perforated by firing a perforation gun or perforation tool. A packer may be set and a formation proximate to the wellbore may be hydraulically fractured. A plug may be set in the wellbore.
Perforation tools may comprise explosive charges that are detonated to fire the perforation tool, perforate a casing if present, and create perforations and/or tunnels into a subterranean formation proximate to the wellbore. In general, a perforating explosive charge may perforate a casing, a subterranean formation, or both. In some circumstances, it may be desirable that the tunnels created in the subterranean formation be deep and as free of debris as possible to promote flow of fluids into or out of the subterranean formation. Different explosive charges may be used to realize different perforation objectives. For example, big-hole explosive charges may produce holes in the casing and formation that are relatively bigger in diameter and relatively shallower than deep-penetrating explosive charges. Deep-penetrating explosive charges may produce holes in the casing and formation that are relatively smaller in diameter and relatively deeper than big-hole explosive charges. Sometimes a perforation gun may employ both big-hole charges and deep-penetrating charges. Yet other kinds of perforating explosive charges may be used in perforation tools.
Debris may comprise fines released from the subterranean formation or created by the perforation and/or residue from the perforation tool, for example, metal shards blown out of the perforation tool by the explosive charges. Debris may also be deposited in the wellbore as the perforation tool is removed from the wellbore, for example metal shards in the interior of the perforation gun falling or bouncing out of holes in the tool body of the perforation gun as the perforation gun is removed from the wellbore.